GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provide an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Rear Compartment Lid Release Actuator Signal

1

2

2

--

Rear Compartment Lid Release Actuator Ground

--

3

3

--

1. Ajar Indicator Always Illuminated

2. Ajar Indicator Inoperative

3. Trunk Release Inoperative

Circuit/System Description

The rear compartment lid can be released by operating the rear compartment lid release switch or by pressing the rear compartment release button on the remote keyless entry transmitter. The gear selector may be in any position, but the vehicle speed must equal 0 for the rear compartment lid to release.

When the ignition is ON, the body control module (BCM) supplies battery positive voltage to the rear compartment lid ajar switch through the rear compartment lid ajar switch signal circuit. When the rear compartment lid is opened, the signal circuit is connected to ground through the rear compartment lid ajar switch ground circuit and the voltage is pulled low within the BCM. In response, the BCM sends a serial data message to the driver information center (DIC) in the instrument panel cluster (IPC) to illuminate the rear compartment lid ajar indicator.

Reference Information

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Door Ajar Indicator Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Rear Closure Ajar Sw parameter while opening and closing the rear compartment lid, the reading should change between Inactive and Active.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
  2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Rear Closure Ajar Sw parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3-amp fused jumper between the signal circuit terminal 2 and the ground circuit terminal 3. Verify the scan tool Rear Closure Ajar Sw parameter is Active.
  7. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  8. If all circuits test normal, test or replace the rear compartment lid release actuator.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
  2. Test for infinite resistance between the signal terminal 2 and the ground terminal 3 with the switch in the open position.
  3. If not the specified value, replace the rear compartment lid release actuator.
  4. Test for less than 2.0 ohms between the signal terminal 2 and the ground terminal 3 with the switch in the closed position.
  5. If greater than the specified range, replace the rear compartment lid release actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Compartment Lid Latch Replacement
    •  Control Module References for BCM replacement, setup, and programming